In FY 2014, we continued our efforts to understand the impact that phenol-soluble modulins have on biofilm development. We have shown the contribution of beta-type PSMs to S. epidermidis biofilm development and all PSMs to S. aureus biofilm development in recent papers in recent papers (Wang et al. J Clin Invest 2011, Periasamy et al. PNAS 2012). We are now trying to complete our set of isogenic deletion mutants in S. epidermidis psm loci to investigate the role all PSMs play in S. epidermidis biofilm development and dissemination from device-related infection in vivo. Furthermore, we collaborated with Dr. Hickok (Jefferson University) on characterizing biofilm formation as a phenomenon underlying difficult-to-treat joint infections.